Many diverse assembly operations require the placement of fragile components or elements into openings formed in rigid structures. Extreme care must be exercised in such assembly operations lest the elements will hit the rigid edges of the openings and will be bent or otherwise damaged. As an example, in the manufacture of transformers, induction coils and the like, thin laminates of magnetically soft material are inserted in openings formed in rigid bobbins that have been previously wound with coils of wire. The laminates are not only magnetically soft but are also physically soft in that the laminates are easily bent upon hitting the edges of the bobbin openings. Even though machines have been designed to automatically insert the laminates in the bobbin openings, their use is rather limited when the laminates are thin and readily susceptible to bending upon the laminates hitting the edges of the bobbin opening. In such situations a jamming easily occurs and the automatic cycling must be interrupted to permit an attending operator to remove the bent laminate. These interruptions occur frequently and, hence, often make the use of such machines economically prohibitive. As a result, resort is made to manual assembly of the laminations. The problem is further compounded where the laminations are in an E-shaped configuration requiring the insertion of the central laminate leg in the bobbin opening while the outer laminate legs are assembled to span the bobbin.
A machine for assembling I and E shaped cores into an opening formed by a transformer winding is shown in U.S. Pat. No. 2,750,659 issued June 19, 1956 to U. Sassi. In this machine, a pair of spaced magnets are oscillated to alternately pick up laminations from the tops of spaced stacks and deposit the laminates adjacent to the opening in the transformer winding. A pair of pusher devices are alternately operated to push the deposited laminations into the transformer winding opening. When the laminates are delivered to the position adjacent the transformer winding opening they are held in position by a pair of magnets that are stronger than the laminate delivery magnets.
Another apparatus for assembling and interleaving laminations within a coil bobbin is disclosed on Pages 3 and 4 of an article appearing in the April, 1973 issue of the Technical Digest No. 30 published by the Western Electric Company, Inc., New York, N.Y. In this instance, a shuttle provided with magnets is reciprocated between the tops of two stacks of E-shaped laminations to alternately pick off the top laminations which are then alternately inserted from opposite sides into an opening formed in the coil bobbin. As the shuttle moves from one stack to the other, the laminations are inserted in the coil bobbin opening and are thus stripped from the magnet carried by the reciprocating shuttle.
In another class of insertion machines, a pair of reciprocating pushers sequentially move laminations from the bottom of a pair of spaced stacks. These lowermost laminations are advanced into a coil bobbin opening interposed between the stacks. Examples of these machines are shown in U.S. Pat. No. 3,136,043 issued June 9, 1964 to R. L. J. Ruellan, and in an article appearing on pages 15 and 16 of the Technical Digest No. 29 published January, 1973, by the Western Electric Company.